In the field of semiconductor processing, flat-panel display processing or other electronic device processing, vapor deposition processes have played an important role in depositing materials on substrates. As the geometries of electronic devices continue to shrink and the density of devices continues to increase, the size and aspect ratio of the features are becoming more aggressive, e.g., feature sizes of 0.07 μm and aspect ratios of 10 or greater. Accordingly, conformal deposition of materials to form these devices is becoming increasingly important.
During an atomic layer deposition (ALD) process, reactant gases are introduced into a process chamber containing a substrate. Generally, a region of a substrate is contacted with a first reactant which is adsorbed onto the substrate surface. The substrate is then contacted with a second reactant which reacts with the first reactant to form a deposited material. A purge gas may be introduced between the deliveries of each reactant gas to ensure that the only reactions that occur are on the substrate surface.
Some processes use multiple gases for various reasons. For example, a CVD process may mix two reactive gases in the process region of a process chamber while adding a third gas as a diluent or catalytic agent. Additionally, some processes may incorporate additional gases post-processing to treat the deposited film or clean the process chamber. Therefore, there is an ongoing need in the art for improved gas distribution apparatuses that can provide a uniform supply of separate gases to the processing chamber.